Currently known medical imaging diagnostic apparatuses include CT (Computed Tomography) scanners, MRI (Magnetic Resonance Imaging) apparatuses, PET (Positron Emission Tomography) apparatuses and the like. For using the abovementioned apparatuses, a contrast medium, physiological saline or the like (hereinafter referred to as a chemical liquid) is often injected into the patient's body. Various types of injectors (chemical liquid injectors) which automatically perform the injection are commercially available.
Patent Document 1, for example, discloses a mechanism for holding a flange of the syringe as a mechanism for fixing the syringe to the injector. The flange of the syringe to be held by the mechanism has cut-portions on both sides of left and right and has two notches formed in its outer circumference (an arc-shaped portion).
The mechanism described in Patent Document 1 has a pair of hooks for engaging with the notches of the flange. To fix the flange on the mechanism, user first holds the syringe in the orientation in which the cut-portions of the flange are located on both sides of left and right, and then moves it downward so that the syringe is inserted between the pair of hooks. At this point, the pair of hooks have not come into the notches yet. Then, user rotates the syringe by 90 degrees about an axis, at that position, to cause the ends of the hooks to come into and engage with the notches thereby fixing the flange of the syringe.
Patent Document 1: Japanese Patent Laid-Open No. 2002-11096